CVE-2025-38581 crypto: ccp - Fix crash when rebind ccp device for ccp.ko

Medium 5.5 Published Updated

A local attacker can cause a kernel crash by rebinding the CCP device when debugfs is enabled, leading to denial of service.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Local or same network only
Victim action needed
Not needed
Fix
Available

What is CVE-2025-38581?

CVE-2025-38581 is a medium-severity vulnerability in Debian Debian Linux, published on 19 Aug 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

crypto: ccp - Fix crash when rebind ccp device for ccp.ko

When CONFIG_CRYPTO_DEV_CCP_DEBUGFS is enabled, rebinding the ccp device causes the following crash:

$ echo '0000:0a:00.2' > /sys/bus/pci/drivers/ccp/unbind $ echo '0000:0a:00.2' > /sys/bus/pci/drivers/ccp/bind

[ 204.976930] BUG: kernel NULL pointer dereference, address: 0000000000000098 [ 204.978026] #PF: supervisor write access in kernel mode [ 204.979126] #PF: error_code(0x0002) - not-present page [ 204.980226] PGD 0 P4D 0 [ 204.981317] Oops: Oops: 0002 [#1] SMP NOPTI ... [ 204.997852] Call Trace: [ 204.999074] <TASK> [ 205.000297] start_creating+0x9f/0x1c0 [ 205.001533] debugfs_create_dir+0x1f/0x170 [ 205.002769] ? srso_return_thunk+0x5/0x5f [ 205.004000] ccp5_debugfs_setup+0x87/0x170 [ccp] [ 205.005241] ccp5_init+0x8b2/0x960 [ccp] [ 205.006469] ccp_dev_init+0xd4/0x150 [ccp] [ 205.007709] sp_init+0x5f/0x80 [ccp] [ 205.008942] sp_pci_probe+0x283/0x2e0 [ccp] [ 205.010165] ? srso_return_thunk+0x5/0x5f [ 205.011376] local_pci_probe+0x4f/0xb0 [ 205.012584] pci_device_probe+0xdb/0x230 [ 205.013810] really_probe+0xed/0x380 [ 205.015024] __driver_probe_device+0x7e/0x160 [ 205.016240] device_driver_attach+0x2f/0x60 [ 205.017457] bind_store+0x7c/0xb0 [ 205.018663] drv_attr_store+0x28/0x40 [ 205.019868] sysfs_kf_write+0x5f/0x70 [ 205.021065] kernfs_fop_write_iter+0x145/0x1d0 [ 205.022267] vfs_write+0x308/0x440 [ 205.023453] ksys_write+0x6d/0xe0 [ 205.024616] __x64_sys_write+0x1e/0x30 [ 205.025778] x64_sys_call+0x16ba/0x2150 [ 205.026942] do_syscall_64+0x56/0x1e0 [ 205.028108] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 205.029276] RIP: 0033:0x7fbc36f10104 [ 205.030420] Code: 89 02 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 8d 05 e1 08 2e 00 8b 00 85 c0 75 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 f3 c3 66 90 41 54 55 49 89 d4 53 48 89 f5

This patch sets ccp_debugfs_dir to NULL after destroying it in ccp5_debugfs_destroy, allowing the directory dentry to be recreated when rebinding the ccp device.

Tested on AMD Ryzen 7 1700X.

Weakness: CWE-476

Which versions are affected by CVE-2025-38581?

It affects 2 products.

Products include Debian Debian Linux, Linux kernel.

How do I fix CVE-2025-38581?

Apply the vendor's patch.

Is CVE-2025-38581 being exploited?

There is no known exploitation of CVE-2025-38581 in the wild and no public exploit code.

All Debian Debian Linux vulnerabilities

Sources

Also known as AZL-66500, BELL-CVE-2025-38581, DEBIAN-CVE-2025-38581, GHSA-p2qj-w526-vfr2, OESA-2025-2123, ROOT-OS-DEBIAN-11-CVE-2025-38581 and 5 more.

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